Electrical feedthroughs for conducting current across gastight barriers are well-known in the art for a variety of different applications. They normally comprise one or more electrical conductors carried by an insulating housing which is fit into an appropriately sized opening in a barrier wall so as to provide a means of conducting current across the barrier. Linear style feedthroughs are generally rectangular in plan and are difficult to seal in gastight seals; thus, it is more often that one finds generally cylindrical body feedthroughs where hermetic seals are necessary. Cylindrical-type feedthrough housings are often made of glass, metal or ceramic and metal combinations. These materials are brittle and such feedthroughs are fragile and expensive.
Ceramic and glass feedthroughs sometimes cause problems of sealing with particular barrier walls due to the various attachments and techniques which must be employed to achieve effective seals. Welding, brazing, soldering and the like are sometimes used.
In more recent times feedthroughs having plastic molded housing have been used with various types of sealing means including various O-ring arrangements.
Often plastic molded feedthroughs employ wires, lugs or pins or a combination thereof which require separate mechanical means for securing the electrical connection effected through these elements. Sometimes it is even necessary to provide a separate plug or socket to contact the feedthrough and carry a plurality of leads to another location where the leads are spread apart as by a terminal block construction to allow interconnection with other electrical devices or to provide for strain relief of the lead wires.